Issue
Some network environments are locked down via a Firewall and allow only whitelisted IP addresses inbound to their internal network. Common questions are, “what is my Azure Web App, Azure Mobile App (insert your type of Azure App Service here) outbound IP address”? What IP addresses do I need to whitelist for Azure? Even if you determine it through a network trace or firewall log, you will notice it can change. This is because of the internal structure of Azure. The outbound address could be any address within a certain range. However, this range is not static.
Solution
For an individual App you can look in the Properties of the application:
What if you need to whitelist a region however (you are constantly adding new apps etc…)?
We provide a list of the Azure Data Center IP ranges. You can download this XML file and find the Data Center that your Azure Web App is in and then whitelist those ranges of IPs. This list is update weekly (mostly with additions). Then you can automate or manually update your firewall with this list to ensure your app is able to call into your network through your firewall.
Here is an example:
The app I want to find the range of IPs for is called problemwebapp. I look this up in the Azure Portal to see what Data Center is in (in the Overview tab) and I see it is in ‘East US’:
Next I go to this link and download the XML File with the Azure Data Center IP listing: Microsoft Azure Datacenter IP Ranges
And search for the location. I searched on ‘us’, then ‘east’ and was able to find this (yes it is a bit cryptic but it will not change):
At this point you have the information for that Data Center and can add these IP ranges to your Firewall. Depending on how your firewall is managed, you may be able to automate this (talk to your firewall provider).
FAQs
What does this list include:
Will I have time to update my firewall before a change happens:
How often can this outbound list change:
Is this only Web Apps or ALL IPs in the data center:
Per Microsoft Azure Datacenter IP Ranges , all of these questions above are answered in the Details section:
https://www.microsoft.com/en-us/download/details.aspx?id=41653 “This file contains the Compute IP address ranges (including SQL ranges) used by the Microsoft Azure Datacenters. A new xml file will be uploaded every Wednesday (Pacific Time) with the new planned IP address ranges. New IP address ranges will be effective on the following Monday (Pacific Time). Please download the new xml file and perform the necessary changes on your site before Monday.“
Is there a way to narrow this list to just Azure Web Apps: No